SLC504 DH+ led red steady

Hi,

does anyone have ever seen the DH+ steady red on a SLC504. What does it means?

In the Slc504 manual, I only can find if the led is flashing red.

thanks
Martin.

I believe it means an unrecoverable hardware failure.

I have often found that you can clear the memory and re-download the program and it will work.

Greetings Martin ...



you’re talking about the “DH+” LED - the middle one - on the right side? ...



personally, I’ve never seen that one glow a “steady” red ... what does it do when you unplug BOTH of the DH+ connectors? ... specifically, the 3-pin cable - AND the little 8-pin round one (if you’re using it) ...



if the LED starts to flash green (about once each three or four seconds) with both cables disconnected, then you probably have duplicate addresses on the DH+ network ... this usually happens when someone uses station #1 - and then a “new” SLC-5/04 is installed on the network ... since the “fresh-off-the-shelf” setting for a new (or a “reset”) SLC-5/04 is station #1, then an “overlap” can occur ...



note: this is why most “been-bit-before” technicians won’t use station #1 in their systems ... they skip #1 and start with #2 ...



anyway ... according to the book, and everything that I’ve ever seen, the LED will FLASH red when there are duplicate station addresses ... specifically, that “steady” red condition that you mentioned is a new one on me ...







whatever this finally turns out to be (bad DH+ port perhaps?) PLEASE come back and post the final answer ... I (and others) would like to know how this one turns out ...

Oh boy, I can't read very well. Sorry. I saw steady red and my mind went straight to a faulted processor.

Ron, I've seen TOO many times. I actually described it in this older post:

http://www.plctalk.net/qanda/showthread.php?t=10666


For me, the fault is usually an interrupt of power while downloading the program (which is NOT what is happening). As the post describes, this problem, that causes the DH+ light to go on steady red, is while assembling edits via the DH+ network (not serially). The only way to recover is to power down the processor and power it back up. Every once in a while I have to take the battery out and default the processor. The meaning of the solid red light is that the DH+ system is no longer communicating and is faulted out.

MGuenette: what are you doing when you see the red light? Are there other nodes communicating via DH+? Read my referenced post and see if it is the same thing. I haven't found a fix, but misery loves company.

brucechase said:

Ron, I've seen TOO many times. I actually described it in this older post:

http://www.plctalk.net/qanda/showthread.php?t=10666


For me, the fault is usually an interrupt of power while downloading the program (which is NOT what is happening). As the post describes, this problem, that causes the DH+ light to go on steady red, is while assembling edits via the DH+ network (not serially). The only way to recover is to power down the processor and power it back up. Every once in a while I have to take the battery out and default the processor. The meaning of the solid red light is that the DH+ system is no longer communicating and is faulted out.

MGuenette: what are you doing when you see the red light? Are there other nodes communicating via DH+? Read my referenced post and see if it is the same thing. I haven't found a fix, but misery loves company.

Click to expand...

See AB's knowledgebase on the above problem I.D. 14319
See PDF below

Mickey said:

See AB's knowledgebase on the above problem I.D. 14319
See PDF below

Click to expand...

Sorry Mickey, as I stated in the original thread (post #3), tried that many times and no luck. Even had AB send GTS out and after a while he gave up. My problem with the red led has never be fixed. I've just learned to live with it.

The old joke about the guy who goes to the doctor and says every time I bend my arm a certain way it hurts; the Dr. says "then stop bending your arm that way" - it applied to this situation (stop doing online edits over DH+).

brucechase said:

Sorry Mickey, as I stated in the original thread (post #3), tried that many times and no luck. Even had AB send GTS out and after a while he gave up. My problem with the red led has never be fixed. I've just learned to live with it.

The old joke about the guy who goes to the doctor and says every time I bend my arm a certain way it hurts; the Dr. says "then stop bending your arm that way" - it applied to this situation (stop doing online edits over DH+).

Click to expand...

Sorry, I only read the first post on that link.

Hi guys,


I have restarted the PLC yesterday morning and everything is ok now. I have seen that I have a cleanup to do in the program. One ladder file is used to communicate with an old equipement that we dont have anymore. The cable is still there.

Actually I have blocked the JSR for the ladder file and I will rearrange the DH+ cable

thanks
Martin.

MGuenette said:

Hi guys,


I have restarted the PLC yesterday morning and everything is ok now. I have seen that I have a cleanup to do in the program. One ladder file is used to communicate with an old equipement that we dont have anymore. The cable is still there.

Actually I have blocked the JSR for the ladder file and I will rearrange the DH+ cable

thanks
Martin.

Click to expand...

What is happening when the red light comes on? Is anything being done or do you just walk by and notice that it is on? Is anything else on the DH+ line? Is there any kind of network?

brucechase said:

What is happening when the red light comes on? Is anything being done or do you just walk by and notice that it is on? Is anything else on the DH+ line? Is there any kind of network?

Click to expand...

When the DH+ led turns RED, I just loose the communication with the PLC (connected on via DH+). The PLC program is still running....

Martin.